C++ remains as relevant today as in its mid-80s advent. The imperative, object-oriented language of programming is generally used as a language for general applications. Therefore, many jobs need a detailed comprehension of C++ by applicants.

TOP Interview Questions in C++ for Freshers

Find best questions and answers for interviews with C++. If you’re training for a job in C++, here are the 20 most critical questions in a C++ interview to self-assess your C++ readiness for your interview:

Q1. Define C++?

Answer: C++ is a C-language computational programming superposition with the incorporation of C-language functions.


Q2. Can we call C++ OOPS? and Why?

Answer: Indeed, OOPS can be called C++. The full form of OOPS is an object-oriented programming system that represents a philosophy that implements multiple principles, including data binding, polymorphism, heritage, and other concepts.

Q3. Define Class in C++?

Answer: A class is known as the user data type design. It reflects various entities, characteristics, and actions.


Q4. Define Object in C++?

Answer: Object is an instance of the class. An object may have fields, methods, builders, and related fields. For example, a motorcycle in real life is an object, but it has brakes, color, size, design, etc.

Q5. Define Encapsulation in C++?

Answer: Encapsulation is the method in which data and functions in a class are bound together. It is used for security reasons to avoid direct access to the data. For this reason, the parts of a course are used. For instance, only the designated individual with the login ID and password must access the consumer net banking facility. It is also only for its portion of the data in the database source.


Q6. What is an abstraction in C++?

Answer: An abstraction in C++ is hiding the internal frameworks and showing only the relevant info. E.g., just writing and clicking on the send option is used when you send an important message by e-mail at that time. This result is just the message to affirm the success of your e-mail. However, it is not shown while transmitting data via e-mail because it is not of interest.


Q7. Briefly explain the concept of Inheritance in C++.

Answer: C++ allows classes to inherit any of the normal state and behavior. This process is referred to as inheritance.


Q8. Define access specifier and its various types in C++

Answer: The access specifier provides how the class members should be used outside the class framework, i.e., functions and variables. There are three kinds of access specifier in C++:

  • Private: Members of such a class cannot be reached outside of the course they are declared and only in the same level are eligible.
  • Protected: Children’s communities will access protected members of their parent class, in addition to the level they are declared in.
  • Public: Public access is given in the program, declared as public (code)


Q9. Define a namespace?

Answer: A namespace is used for addressing the name dispute of the identifier by placing it under separate namespaces. It helps in dividing various codes logically.


Q10. Define a class template?

Answer: A class prototype is a common class name.  The use of the keyword template is made for defining a class template.


Q11. What is the function of the keyword “Volatile”?

Answer: “Volatile” is a function for declaring that the specific variable is volatile and thereby orders the programmer to modify the variable externally. The compiler optimization on the reference variable will thus be stopped.


Q12. Define storage class in C++? Name some?

Answer: C++ storage class explicitly looks like existence or even symbols scope, including variables, functions, etc. All C++ storage classes’ names are mutable, automated, static, external, log, etc.


Q13. Define an Inline Function in C++? Write its syntax. Is it possible for the C++ compiler to ignore inlining?

Answer: C++ provides inline functions to reduce the function call overhead. As the name suggests, an inline part is enlarged in line when it is called.

The whole code of the same function is added or replaced at the inline function call stage until the inline process is called. At compile time, the replacement is done with the C++ compiler. Small inline functionality will improve the efficacy of the software.

The syntax of a typical inline function is:

Inline return-type function-name(parameters)
// Function code goes here


Q14. Can we have a recursive inline function in C++?

Answer: Even though it can reach an inline function from inside C++, the compiler may still not generate the inline code. It is because, at compilation time, the compiler can not decide the resource depth.

Nonetheless, a compiler with a strong optimizer will inline recursive calls until some compile time is set. When the real center is longer than runtime, insert non-recursive needs at the time of compilation.


Q15. Explain ‘this’ pointer?

Answer: The ‘this’ is a permanent pointer, including the current object’s memory address. It transfers all non-static function calls as a concealed statement. In the body of all non-static parts, it is also conceivable as a local vector.

The ‘this’ pointer is not available for them because static member functions can be called even with no entity, i.e., with the class name.


Q16. What are the most important differences between C and C++?


C++ accepts references while C does not accept references

C++ is intrinsic to functionality such as friend functions, overloading, inheritance, templates, and synthetic processes. The C programming language is not available.

In C, excellent treatment of the conventional if-else form is taken care of. C++, on the other hand, provides support for language exceptions.

The scanf() and printf() are mainly used input and output in C. C++, cin is the regular stream of feedback, and cout is the default stream of production.


Q17. Why do we need the Friend class and function?

Answer: Often, a certain class wants to have access to private or safe class members. The alternative is a friend class that can contact the privately-owned and covered members of the course. They are considered friends.

A friend function can access private, secure, and safe class members in the same way as a friend class. A friend function may be a global function or a class process.

Few important things about class and friend work:

  • Friendship is not inherited.
  • Friendship is not mutual, which means if some Friend class is a friend of some other, not Friend class, it is not always a Friend class friend.
  • The software can have limitations on the total number of classes for friends and associates because the overabundance of the curriculum could reduce the expectation that different courses should be encapsulated, which is an intrinsic and desirable quality in object-oriented programming.